Assemblies and methods of stabilization

Patent metadata

Field	Value
Publication number	US-2015294796-A1
Application number	US-201314646047-A
Country	US
Kind code	A1
Filing date	Nov 21, 2013
Priority date	Nov 21, 2012
Publication date	Oct 15, 2015
Grant date	—

Abstract

Some embodiments of the present invention provide an assembly for harvesting light comprising a first molecule joined to a metal oxide surface through a surface linking group and a second molecule joined to the metal oxide surface. Such assemblies can harvest light to do useful chemistry, such as in a dye-sensitized photoelectrochemical cell, or a molecular catalyst-solar cell system. In other embodiments, the harvested light can be converted into electricity, such as in a dye-sensitized solar cell. Other embodiments of the present invention provide methods for stabilizing a chromophore or a catalyst on a surface. These methods are applicable, for example, to dye-sensitized photoelectrochemical cells where the surface-bound chromophores are known to be unstable under aqueous conditions.

First claim

1 . An assembly comprising:
a metal oxide surface; at least one first molecule attached to the metal oxide surface through one or more surface-linking groups, at least one second molecule attached to the surface wherein the second molecule is an oxide.

2 . The assembly of claim 1 , wherein the at least one first molecule is a chromophore or catalyst.

3 . The assembly of claim 1 , wherein the at least one second molecule is conducting.

4 . The assembly of claim 1 , wherein the at least one second molecule is semiconducting.

5 . The assembly of claim 1 , wherein the at least one second molecule is insulating.

6 . The assembly of claim 1 , wherein at least some of the metal oxide is in the form of nanoparticles, nanocrystals, nanocolumns, nanotubes, nanosheets, nanowires, nanotips, nanoflowers, nanohorns, nano-onions, dendritic nanowires, or a combination of two or more thereof.

7 . The assembly of claim 1 , wherein the metal oxide is chosen from SnO 2 , TiO 2 , Nb 2 O 5 , SrTiO 3 , Zn 2 SnO 4 , ZrO 2 , NiO, Ta-doped TiO 2 , Nb-doped TiO 2 , fluorine-doped tin oxide, indium tin oxide, antimony-doped tin oxide and combinations thereof.

8 . The assembly of claim 1 , wherein the surface linking group is chosen from —COOH, —PO 3 H 2 , —SO 3 H, —OPO 3 H, —OSO 3 H, —PH(OH) 2 , —CH(CO 2 H) 2 , —CH═C(CO 2 H) 2 , —CONHOH, —CSSH, CSOH, and combinations thereof.

9 . The assembly of claim 1 , where the at least one second molecule is chosen from: oxide dielectrics, oxide conductors, oxide semiconductors, ternary oxides, nitride dielectrics, nitride semiconductors, metallic nitrides, group II-VI semiconductors, group II-VI based phosphors, group II-V semiconductors, fluorides, CaF 2 , SrF 2 , MgF 2 , LaF 3 , and ZnF 2 , elements, PbS, SnS, In 2 S 3 , Sb 2 S 3 , Cu x S, CuGaS 2 , WS 2 , SiC, Ge 2 Sb 2 Te 5 , and combinations thereof.

10 . The assembly of claim 1 , wherein any one of claims the at least one second molecule is chosen from Al 2 O 3 , ZrO 2 , and HfO 2 and combinations thereof.

11 . The assembly of claim 1 , wherein the at least one first molecule is chosen from ruthenium coordination complexes, osmium coordination complexes, copper coordination complexes, porphyrins, phythalocyanines, and organic dyes, and combinations thereof.

12 . The assembly of claim 1 , wherein one or more of the at least one second molecule is bonded to one or more surface linking groups.

13 . The assembly of claim 1 , wherein one or more of the at least one second molecule is bonded to another second molecule.

14 . The assembly of claim 1 , wherein the desorption rate constant of the at least one first molecule measured in water (k des ) is equal to or less than about 3.9×10 −5 s −1 .

15 . The assembly of claim 1 , wherein the desorption rate constant of the at least one first molecule measured at pH 8.5 (k des ) is equal to or less than about 10.9×10 −5 s −1 .

16 . The assembly of claim 1 , wherein the cross surface electron diffusion coefficient (D app ) is equal to or less than about 1.32×10 −10 cm 2 /s.

17 . The assembly of claim 1 , wherein the electron ejection efficiency (φ inj ) is equal to or greater than about 47%.

18 . The assembly of claim 1 , wherein the back electron transfer rate (k bet ) is equal to or less than about 4.8×10 4 s −1 .

19 . The assembly of claim 1 , wherein the electron ejection efficiency (φ inj ) is equal to or greater than about 47% and wherein the back electron transfer rate (k bet ) is equal to or less than about 4.8×10 4 s −1 .

20 .- 22 . (canceled)

23 . An assembly comprising:
a metal oxide surface comprising TiO 2 ; at least one [Ru(bpy) 2 (4,4′-(PO 3 H 2 ) 2 bpy)] 2+ linked to the metal oxide surface, and at least one Al 2 O 3 linked to the surface.

24 .- 29 . (canceled)

Assignees

• Univ North Carolina
• Univ North Carolina State

Inventors

• Hanson Kenneth
• Meyer Thomas J
• Parsons Gregory N
• Losego Mark D
• Kalanyan Berc
• Kim Do Han

Classifications

• H01G9/2036 Primary

  comprising mixed oxides, e.g. ZnO covered TiO2 particles · CPC title

• Y02E10/549

  Organic PV cells · CPC title

• H01G9/2031

  comprising titanium oxide, e.g. TiO2 (H01G9/2036 takes precedence) · CPC title

• Y02E10/542

  Dye sensitized solar cells · CPC title

• H01G9/2059

  comprising an organic dye as the active light absorbing material, e.g. adsorbed on an electrode or dissolved in solution · CPC title